In my case most of my sales are zero rated and I use the retail scheme apportion some of the sales as standard. So I record all my sales with a "retail" code that has a zero rate. Then at the end of the quarter I do the calculations manually to find the VAT apportionment. I then do a journal entry debiting the 'retail' sales, crediting standard VAT sales obtained from the calculations and to which I apply a a standard 20% rate. Seems to work.
